The present embodiments relate to a C-arm x-ray device having a C-arm and an x-ray source and an x-ray detector arranged on the C-arm.
The problem with x-ray imaging technology is that when x-ray images are produced using a C-arm x-ray device including an x-ray source arranged at one end of the C-arm, vibrations are generated. The vibrations are transmitted via the C-arm to an x-ray detector arranged at the other end of the C-arm. The vibrations develop on account of a high rotational speed of a rotary anode arranged in the x-ray source. The vibrations transmitted to the x-ray detector via the C-arm cause the x-ray detector to continuously move to and fro and thus to deflect from a basic position. X-ray images produced during such vibration phases are characterized by a poor image quality.
When x-ray image sequences are imaged (e.g., a number of x-ray images in temporal sequence) such as is implemented, for example, in angiography typically with a sequence length of 10 seconds and a frequency of 15 to 30 images per second, the vibrations also result in the entire sequence of the x-ray image sequence being negatively affected. The x-ray image sequence appears to be blurred when reproduced.
A further disadvantage is that the vibrations cause the bearing and other components of a drive module of the x-ray anode to be exposed to high loads. These mechanical loads are intensified further by the high operating temperatures of the x-ray tube, so that an increased and premature wear of individual components finally results.
The mechanical instability caused by the vibrations in the anode drive housing may result in a higher noise level, which in the case of a patient to be examined, may result in increased unrest, and in the case of an operator of the x-ray facility, may result in increased distraction.
JP 2005-027914 A discloses an x-ray device having a C-arm, in which a vibration sensor and a vibration compensator are arranged on the x-ray detector. The vibration sensor measures the vibration transmitted to the x-ray detector. The measuring results are used to actuate the vibration compensator such that the vibration compensator neutralizes the vibrations.
DE 60131278T2 describes an anode drive module having a rotating anode plate for use in an x-ray tube. The anode drive module includes a rotor that is connected to the rotatable anode plate via a shaft section. The shaft section includes a material with a first thermal expansion coefficient. The anode drive module includes a bearing shaft that is held rotatably by a bearing surface. The bearing shaft includes a material with a second thermal expansion coefficient. A boss that connects the bearing shaft to the rotor is made of a material with a thermal expansion coefficient that lies between the first and the second thermal expansion coefficients. As a result, the appearance of unequal thermal expansion rates between the components is reduced. As a result, mechanical instabilities are reduced in the drive module, thereby providing a high image quality of the x-ray image produced.